Hydraulic well pumping mechanism



June 23, 1942. L. A. RINGMAN HYDRAULIC WELL PUMPING MECHANISM Filed Jan30, 1940 7 Sheets-Sheet 1 IN VENTOR.

XM 1 7? WM,

' ATTORNEY.

June 23, 1942.

L. A. RINGMAN HYDRAULIC WELL PUMPING MECHANISM "7 Sheets-Sheet 2 FiledJan. 50, 1940 IN VENT OR.

-44, ATTOR EY.

June 23, 1942. 1.. A. RINGMAN HYDRAULIC WELL PUMPING MECHANISM FiledJan. so, 1940 7 Sheets-Sheet 3 INVENTOR. Z H P 5, BX/M4 M- M ATTORNEY.

June 23, 1942.. L. A. RINGMAN 2,237,709

' HYDRAULIC-WELL PUMPING MECHANISM Filed Jan. 50, 1940 u '7 Sheets-Sheet4 IN VE NTOR.

J1me 1942- Q L. A. FIQINGMAN HYDRAULIC WELL' PUMPING MECHANI SM FiledJan. 30, '1940 7 Sheets-Sheet 5 X I. PINVENTOR. BY

1 ATTORNEY.

I June 23, 1942..

L. A. RINGMAN HYDRAULIC WELL PUMPING MECHANISM Filed Jan. so, 1940 lZO45- 7 Sheets-Sheet 6 INVENTOR fl, BY;

W ATTORNEY June 23, 1942. RlNGMAN 2,287,709

HYDRAULIC WELL PUMPING MECHANISM Filed Jan. 50, 1940 7 Sheets-Sheet '1127 ;&5 125 125 .zzs JEkb .117 ,l 127 I 127.

INVENTOR BY W TTORNEY Patented June 23, 1942 nrnanumc WELL PUMPINGMECHANISM-4 Louis A. Bingman, Toledo, Ohio, asslgnor to The v NationalSupply Company, Pittsburgh, Pa., a corporation of PennsylvaniaApplication January to, 1940, Serial No. 316.323

3 Claims.

This invention relates generally to a hydraulic pump and moreparticularly to a hydraulic mechanism for pumping wells.

Another object of vision of a fully hydraulically controlled pumpingmechanism.

Another object is the provision of a fluid operated and controlledpumper which is iully automatic. I

Another object is the provision of a fluid this invention is theprooperated and controlled well pumper which utilizes the well load foroperating the pump piston in onedirection.

Another object is the provision of a fluid controlled pumping mechanismcapable of being automatically operated through any one of a series ofselected strokes.

Another object is the provision oi'a fluid controlled pumper operated bya fluid pressure.

Another object is the provision of a fluid pumping mechanism wherein thestroke and the motion of the pumper are operated by the same workingfluid.

Another object is the provision of means for controlling the descendingmovement of the pumper piston.

hydraulic pumping mechanism similar to that shown in Fig. 2 with theoperating control mechanism housed in a single casing. The control inthis instance is .set at the idle position with the pump piston at thelower end of the cylinder. p

Fig. 4 is a view similar to Fig. 3 illustrating the position of thecontrols during the upstroke oi the pump piston for a. selected strokelength.

Fig. 5 is a view similar to Fig. 4 illustrating the reversal of thecontrol mechanism to check the'ascent of the pump piston and to causeitto descend from the top of the selected stroke. Fig. 6 is a view similarto Fig. 5 showing the position of the controls during the time the pumppiston is descending and illustrating how its motion is retarded.

Fig. 'l is a view similarto Fig. 6 illustrating the automatic operation01 the control mechanism for decelerating and finally stopping thepiston at the lower end or the selected stroke just prior to itsreversal, the control valve appreaching theposition similar to thatshown in Another object is the provision of means for I "deceleratingthe'piston'to a stop at the bottom oi its stroke.

Another, object is' the provision of a fully hydraulic pumping mechanismwhich is selfcontained, having no atmosphere.

Another object is communication with the the provision of afullysellconta'ined hydraulic pumping system. capable of circulating theworking liquid during the idling and downstroke periods and whenexcessive pressures build up within the system.

Another object is the provision of new and improved structural apparatusmaking up a V trols set for moving the pump piston to the top Fig. 4,thus representing a complete cycle of the operation of the pump piston.

Fig. 8 is a view similar to Fig. 3 with the conof the cylinder withoutreversing the movement of the piston, thereby causing the relief valveto function due to the development ofv an ex cessive fluid pressure inthe system.

Fig. 9 is aside elevation of an actual pumping unit showing the pump andreservoir con- 1 nectedthereto. Fig. 10 is a diagrammatic-view of acomplete pneumatically operated pumping mechanism.

,Fig. 11 is an enlarged sectional view of the hydraulic pumper and themethod of operating the same.

Other objects andadvantages appear in the following description andclaims.

In the accompanying drawings a I practicalr I embodiment illustratingthe principles. or this invention. is shown wherein:

Fig. l is a diagrammatic view of a-hydraulic pumping mechanism showing asimplified control mechanism comprisingthis invention.

Fig. 2 is a viewsimilar to that shown in Fig. 1

with the provision of additional means for obtaining different strokelengthsof the pump piston and for decelerating the movement piston atthe lower end oi the down stroke.

top of the pump cylinder shown in Fig. 10.

Fig. 12 is a diagrammatic view illustrating a battery. of fluid operatedpumping mechanisms actuated from acommon source of fluid pressure pp y-Fig. 1a shows a horizontally disposed fluid pumping mechanism arrangedto operate a plurality of pumping jacks.

Referring to Fig. 1 of the drawings, lli'represents a well casing whichis closed at its upper end by the well casing head It having a centrallydisposed opening therein arranged to carry slips or other suitable meansfor receiving the well tubing l2 forming the pump barrel within thewell.

Fig.8 is a diagrammatic view of a complete This tubing is suitablypacked to pre-.- vent the escape .of fluid under pressure from the well.A-tubing adapter i3 is secured to the IB preferably welded to the lowerend thereof for securing the same in an annular seat or shoulder I9 ofthe adapter. The latter is provided with a dashpot chamber below theopenend of the cylinder I5. p

The upper end of the cylinder I5 is enclosed by the ,cap 2! secured bybolts to an annular flange 22 welded or otherwise fastened to thecylinder. the eye 23 for hoisting the pump as a unit. A shoulder 24 isprovided in the bore of the cap defining a chamber thereabove.

The motor piston 25 is arranged to reciprocate within the cylinder I5and has secured thereto the polish rod 26 which extends down through thepackings held by the glands I 6 and I7 and into the tubing l2 where itis fitted with a suitable pump plunger. It will be noted from thedrawings that the shoulder 24 and the bottom of the dashpot chamber 20are engaged by the piston 25, thereby determining the limitin positionof the piston in the cylinder and these limits are obviously determinedby thelength of the cylinder I5.

The valves which control theoperation of the j motor piston are shown intheir simplest form in Fig. 1' wherein 28 represents the pilot valvespool slidably supported in the valve chamber .28, and 30 represents themaster valve spool operated by a suitable prime mover as indicated bythe motor 35. The .working liquid is contained in the sump or reservoir38 which is provided with two compartments formed by the dividing wall11. The liquid is withdrawn from the compartment 38 and received uponits,return from 'the' system into compartment 40-. Thus any foreignmatter carried back to the reservoir is retained in compartment 40 bythe dividing wall and may be removed through-a, suitable sludge openingnot shown. v

The liquid is withdrawn from the compartment 3801" the reservoir throughthe line' I I to the pump 34 where it is forced under pressure throughthe line", the relief valve 43, the line 44, to the recess in thechamber ll of the master valve 30, whence it passes to recess 46; line"to the dashpot'20 below the piston25 in,

The top of the cap is provided with tains the master valve spool 30 inthe extreme position at the left of the chamber.

Any'liquid that may have been trapped between the left end of the mastervalve spool 30 and the chamber 3| is forced out by the movement of thespool through the line 53, to the recess 54 in the chamber 29 of thepilot valve and continues through the recess 55, the line 56, the recess51 in the master valve chamber 3i, the line 58 to the common return line60 leading back to the compartment 40 of the reservoir 36. This circuitis of course not subjected to pressure at this time. I

A line 6i connects the pressure relief valve 43 to this common returnline 60 for by-passing the liquid if the pressure in the system reachesa predetermined maximum.

When the lower edge of the piston 25 has passed above the line 62opening into the cylinder I5 adjacent its upper end, the liquid underpressure within the cylinderpasses through line 62, the check valve 63,line 64 to' the chamber 29 of the pilot valve at the left end thereof.The pressure on the liquid causes the pilot valve spool 28 to move tothe right, compressing the spring 32 as shown in Fig. 2. 7,

When the pilot valve spool' 28 is moved to the right the liquid under'pressure travels from recess 46 through line 48, recess in the pilotvalve chamber 29, thence to recess 54, line 53, to the master valvechamber 3| and'works against the left end of the master valve spool 30,causing it to move to the right.

Any liquid trapped between the right end of the master valve spool 30and the chamber 3| is forced out through line 52; recess 5i in the pilotvalve chamber 29. thence to recess 65, line 66, recess 61 in chamber 31to the common return line and back to compartment 40' of the reservoir36. g I

When the master valve spool 30 has been moved to the right as shown inFig. 2 the liquid under pressure travels from the recess 45 in thecylinder I5. thereby lifting the piston 25 to actuate the polish rod onits: upstroke lifting the well loadr The liqu idv under pressure alsopasses from the recess 46 through the line 48 to the recess 50 in thechamber '29. of thepilotvalvewhere it continues through theirecess 5|,the line 52 to the master: valve chamber (at the'right end thereon. Thepressure -,oi the liquid ,thus mainchamber 3| to recess 51 and thencethrough line 58 to the common return line 60. Thus the master valvespool having been reversed after the' piston 25 is raised above line 62in the cylinder I5, by-passes the liquid to the reservoir. The

liquid thus circulates freely in this circuit while the piston 25descends. I

The liquid in the cylinder I5 below the piston :25 is expelled from thecylinder I5 by the weight of the piston, polish rod and parts fastenedthereto plus the liquid carried thereby within the well tubing. Theexpelled liquid from cylinder I5 passes through the dashpot 20, line 41,recess 46 in chamber 3|, to rece'sst'l, and thence through thecommon-return line 60 to the reservoir. The beveled surface on the spool30 throttles the liquid'passing therethrough from This throttling actionrecess 46 to recess 61. limits the speed of the movement of the piston25 during its downward'stroke'. This throttling action may be changed bythe screw flg'thereby providing an external adJustment"of'the open ingbetween'the beveled 30' toretain it in the reversed position? againstthe leftendof the master-valve spool:

When the piston 2B desc'ends it creates a partial vacuum thereabove.

As the upper'edge ofthe piston 2lpasses' be surfacell'and the chain ber31 to regulate the speed of thefdown' stroke The liquid being dischargedfrom the cylinder' aas'moe- 1 The flexibility in low the line I openinginto the cylinder 15nd- ;Iacent the lower end thereof, the partialvacuum above the piston draws the liquid from the left end of the pilotchamber 29 through line 54.

line '|l,check valve 12, line 19 to the space above the piston 25 in thecylinder l5. The spring 32 also aids in moving the liquid in thiscircuit. However the spring 32 could not move the pilot valve. spool 28until pressure was relieved from line I9.

After the pilot valve spool 25 has been returned to the position shownin Fig. 1, the liquid in the left end of the master valve chamber 3| isvented through the line 53, recesses 54 and- 55 in the pilot valvechamber 29, line 55, recess 51 in the master valve chamber 3|, line 53,the

the application of this system isobvious... v In addition to the newlyadded stroke control lines, Fig. 2 also shows an added control forregulating the speed of the movement oi the master 'valve spool 25in'traveling from right to left which action determines the decelerationof the piston 25 at the end of the down stroke 'by retarding the flow ofthe liquid from the cylinder l5 between the recesses 45 and 51. If

the beveled section 58 cuts of! this flow abruptly by sliding over theland section between these recesses the piston'would stop suddenly,producing a shock. To avoid this shock a tapered throttle screw 50 isprovided in the left 'end of y the master valve casing to restrict thepassage common retum line 50 back to compartment 40 r sufllcientpressure on the liquid forced out of the cylinder by the piston 25 tomove the master valve spool 39 to the left into the position shown inFig. 1.

This description completes a full operating cycle of thehydraulic pump.It will be noted however that when the piston 25 passed below lines 52and some of the operating liquid passed into the cylinder l5above thepiston 25. When the liquid accumulates sumciently to spill out the line13 with the piston at the top of its stroke it passes down through checkvalve 14, line 15 to the' common return line 59 to the reservoir- Itwill benoted that this pumping mechanism is entirely. hydraulicallycontrolled and operated. The hydraulic system is self-contained.

and has no communication with the atmosphere, which precludes thepossibility of sand or water vapor entering the system.

The pilot valve spool serves only to control the position of the mastervalve spool which in turn controls the direction of the flow 'of liq-'uid under pressure, thereby controlling the direction of the movement ofthe piston and the rate of speed that the piston descends, which isadjustable by means of the screw- 33.

Referring now to Fig. 2 it will be' noted that additional stroke controllines 15 and I1 have been added and they enter the cylinder 15 atpositions intermediate the stroke control lines 52 and 10. Valve 18connects either stroke control line 52 or 15 with the check valve 53through the line 59, andvalve 19 connects either stroke control line 10or Tl with check valve 12 through the line 59. Thus by selecting theproper stroke control lines vwiththe stroke control valves 18 and 19 thepiston 25 may be made to operate in any. one of four strokes such ascontrolled by lines 52 and 19, 52 and 11,15 and Ill or 15 and 11.

?If the distance between the entry of lines 52 .and

of the fluid therefrom. Thus the smaller the orifice the slower themovement of thespool 30 to the left resulting in gradually stopping theflow of liquid from the cylinder l5, thereby grad ually decelerating andfinally stopping the down- 15 into cylinder" l5 is different than thedis- 'tance between the entry of' lines 10 and 11, then each of the fourstrokes will be, of different lengths. In this manner any number .ofstroke control lines may be added to produce any length of strokedesired. Again several of these stroke control lines may be added at oneend of the cylinder l5with only one stroke line at the other.

ward'movement of the piston 25.

A small leakage hole 89' is provided in the throttle screw 85 to preventstalling of the master valve spool in case one happened to turn the rtapered screw completely into theopening.

A check valve 8| is arranged to by-pass the needle throttle valve 80 topermit the master valve spool 30 to be quickly shifted to the right whenthe piston isat the top of its stroke and is about to reverse.

In Fig. 1 the structure is shown in its simplest form to demonstrate theprinciples of this invention. In Fig. 2 the stroke control, and thepiston decelerating mechanisms have been added to illustrate thecomplete invention. However in these two views the relief valve, thepilot and master valves. the stroke control valves and the various checkvalves have been shown as separate or individual structures. Each ofthese structures has been combined-in Figs. 3 to 8 into a single housing82 which in practice is secured to one side of the cylinder anchor andthe line connections running to the various levels of the cylinder'lSmay be'made by small copper lines as illustrated in Fig. 9. The linesare enclosed in the long box or conduit 83 extending up one side of thecylinder l5 and the lines 42 and 50 connecting the pump and thereservoir with the housing 92 may be flexible hose connections toprevent vibration from 'being transmitted between these two parts of themechanism. The pump and the reservoir have been combined into onehousing as illustrated at Blkwhich is se- I cured to the same baseas themotor 35.

Referring now to Figs. 3 to 8, the stroke control valves 19 and 19 areshown as cylindrical plugs rotatably mounted in a common chamber 85. andhaving radial ports, disposed in angular relation to each other,andwhich connect with a common passage in the center of thelplugsrepresenting a portion of the lines 59 and 59 respect vely as previouslydescribed relative to Fig. 2. For convenience the radial passages in thecylindrical plugs of the valves 18 and 19 are disposed at ninety degreepositions.- However the more.

control lines added may necessitate reduction of this angular spacing.

Each valve 15 and 19 is provided with a stem having an indicating dialsecured thereto as shown at'35 and 91. These dialsare marked as shown inFig. 2. The numbers 52 and 15 on dial 35 indicate selection of thestroke control lines of the same number at the top of the piston strokemade by turning this dial. The dial 3! thereon. a

bottom of the piston stroke. In actual practice the. stroke, positions-or lengths may be stamped A valvedr ain i'gedines: opens into thechamher as between ,theplugs of the valves is and 1sandconnectswiththerecess 65 in the pilot valve control chamber 29.andthus passes directly to the common return line 50.

The casing 12,15 also providedwith a drainage p line as connecting theright end or the 'pilot valve chamber 29 with'the line 96'. thence tothe com- .mon return line 69 to avoidtrapping any liquid that may leakpa spool valve 29.

The master valve spoolspring 99, which is supported on the abutmentscrew 33, is provided st the last abutment of the pilot to causeleftward motion of the master valve spool incase the reversing action ofthe spool is so slow that the piston 25 reaches the bottom of thedashpot20 before the spool is in position for the upward stroke, atwhich time the deficiency in the discharge pressure of the liquid belowthe pistonis compensated by the force of the spring 99. v

The relief valve 43 shown in detail in Figs. 3 to 8 is made'spool-shapesimilar to the pilot and master valves. This valve is held to the leftby the spring 9| which may be adjusted by the screw 92 to obtain apredetermined pressure on the spool, causing it to function as a safetydevice to protect the system from excessive pressures. when the pressureof the system exceeds the predetermined amount as set by the loading ofthe springthe liquid under pressure becomes effec- 4 tive against thedifferential piston 93 at the left of the spool 43 through the line 94connected to the main line 42. The small differential-piston 93 maybeomitted if desired. The spool 43 is then moved to theright against thepressure of the spring 9| and the liquid under pressure is b'y-passedfrom the recess 95 to the recess 95, which is represented by the line 6|in Figs. 1 and 2. .A drainage line 91 is provided for the right endofthe spool valve" toprevent trapping of any liquid that may have leakedpast the valve. Excessive pressures may occur when one fails to properlyset dial 96 and the piston 25 reaches the top of its stroke as indicatedin Fig.8, or at any point of theupstroke where the load of the polishrod is excessive, such as may be encountered'when awell sands up.

Again referring to-Fig. 3 a. line 99 is shown connecting the line '41,adjacent the dashpot 29 in the adapter i 3, with a radial opening in thestroke control plug valve 19 leading .to the line 69. check valve 93,line 94 to the left end of the pilot valve chamber 29. This line 99 isconnected onlywhen the dial 9515 set at the idling position,

the recess,45 to the recess 51 and thence through the line 59 to thecommon return line 60. The

lines 16 and 11 respectively as shown in Fig. 4

' the pressure of the working fluid formerly effective through the line99 on the left end of the pilot valve spool 29 is cut off by therotationof the dial and at the same time line" is cut into the circuit but thereis no pressure in this line or above the piston 25. The spring 32 thusforces the pilot valve spool 29 to the left, pushing the working liquidout of the chamber 29, through line 64, line IL-check valve 12, line 59,stroke control valve 19, line H to the cylinder I5 above the piston 25.

Themovement of the pilot valve spool 29 connects the left end of themaster valve chamber II with the common retum and admits the workingliquid under pressure to the 'right end of the master valve spool 39,thereby moving it to the left. When the recess 45 is cut off from therecess 51, the pressure of the working fluid builds up sufiicient forcetolift the piston 25 onits upward 1 under pressure to the left end ofthe pilot valve chamber 29 moving the pilot valve spool 29 to the right,thereby admitting liquid under pressure to the left end of the mastervalve chamber 9|, moving the master valve spool 90 to'the right whileconnecting the right end of the master valve chamber to the commonreturn line 99. The illustration in Fig. 5 shows the master valve spooljust about to open the by-pass between recesses 45 and 51 and close theconnection between recesses 45 and 49.

Any excess liquid in the cylinder l5 above the piston 25 will at thistime be drained of! through the line 13, check valve I4 and on to thecommon return 69.

The master valve spool continues to move to the right until it reachesthe position shown in .Fig. 6. The working liquid is then completelyby-passed to'the common return 59 and the liquid from the cylinder I5 isbeing forced through the line 41, recess 49, past the beveled surface 89of the valve, recess 61 to the common return 99 with the pressurethereon'being effective on the left end of the master valve spool 39 tomaintain it to the right in the position shown.

After the piston clears the stroke control line 11 in, the cylinder l5on its downward stroke as shown in Fig. 7 the liquid formerly trapped atthe left end' of the pilot valve spool 29 and holding it to the right isdrawn back into the cylinder l5 through the line 11 because of thepartial vacuum therein and because of the force exerted by the pilotvalve spring 32. I

Thus the pilot valve spool 29 moves to the left as shown in Fig. "7,thereby connecting the i left end of the master valve cylinder 3|with'the working liquid is also effective through the recess 49 of themaster valve, the line 49, the recesses 59 and 54 of the pilot valve,the line,

. the check valvell tothe left end of the master valve chamber 3| andthus being effective to forcevthe master valve spoolto the rightcompressingfthe spring '99..

when the dials99 and 91 are set to connect common return 99 andconnecting the liquid discharged from the cylinder 15 to the right endof the master valve chamber 3| to aid in moving the master valve spool90 to the left. The movement of this valve toward the left end of thechamber is of eourse impeded by the restricted flow past the needlevalve 99, which action gradually cuts off the flow of the liquid pastthe beveled surface 69 on the master valve spool. .When this flow iscompletely out off the working liquid from the pump is about to beadmitted from the recess" 'to the recess 46 as shown in Fig. 7, at whichtimefthe pumped liquidunder pressure will cause the piston toagainas'cend within the cylinder l5.

This description thus completes the action; of

. accumulator.

the control apparatus for a full cycle of the operation of the piston25.

Gages I and I 0| may be placed at difierent parts of the system todetermine the pressure.

Gage I00 is placed adjacent the discharge of the pump 34 in the line 42which registers a positive pressure at all times. ,The gage IIII placedat 2 .the top of the cylinder I in line 13 must be capable of readingnegative or sun-atmospheric pressures as well as pressures thereabove.

Referring now to the pneumatic pumping the structure is the same as thehydraulic mechanism with the exception of the'master valve 30 and thesource of fluid pressure supply. The

master valve 30 of the pneumatic controlsystem ated mechanism to apneumatically operated .mechanism. The control valves and the pumpenisms the pilot valve spring 32 may be replaced mechanism shown in Fig.10, it will be noted that w 7 is provided with a continuous land sectionIII! which prevents communication between therecess 45 containing fluidunder pressure and the recess 51 leading through line 58 to thedischarge line 60. This continuous land section prevents the escape ofenergized fluid from the source of supply while, the piston 25 is movingdownwardly. In the hydraulic system the fluid may circulate but in apneumatic system the fluid energy must not be needlessly wasted.

This pumping mechanism is arranged to be operated from any suitablesource of gas under pressure. This source of supply may be obtained froma high pressure gas well or a compressor station which produces a headpressure on either gas or air. The compressor pumping station 1preferably provided with the type of apparatus by the differentialpiston I2| which is actuated by fluid under pressure eflective throughthe line I22 which is connected tothe line 51. The left end of the pilotvalve 28-and the'right end of the differential piston I2I are subjectedto the same fluid pressure when-the piston passes the selected uppercontrol line 62 or at the end of its upward stroke, but the pilot valve28 will move to the right because the area-of the left end 3 of thepilot valve is greater than that of the differential piston. Thepressure in the cylinder I5 under the piston as it descends maintainsthe check valve '12 in its closed position and the pressure effectiveagainst the left end of the pilot valve maintains it to the right untilthe piston 25' passes below the selected lower control line -'II'I 'or11, at which time the low pressure above the piston discharges thepressure from the left end of the pilot valve 28. The pressureeifectiveirom usually employed for such purposes, including an The fluidunder pressure is conveyed to the control mechanismvthrough the conduitI I I to the pressure regulator I|2 whence it travels through the pipe42 to the control mechanism. 1

The disposition of the pneumatic working fluid depends upon thecharacter of fluid employed. If the source of supply is a high pressuregas it is discharged through the line 60 to the valve H3 where it maypass to the lower pressure line .I I4. This line may be a commondischarge line from a plurality of similar pumping units. Again theexhaust gas may lie-returned through the line 5' to the compressorstation for recompression. If a combustible gas is used it may be pipedto an accumulator where it is finally discharged to a furnace engine orother similar use. The line H6 connected tothe valve H3 is arranged todischarge the pneumatic fluid to the atmosphere. p v a Shut-off valves II1 and I III are provided in the lines 42 and 50, respectively, topermit the pumping unit to be disconnected from the fluid system.

The pressure relief valve 43 is'provided with a communication I I5between the extreme end faces to equalize the pressure acting thereon.This structure is required when the exhaust fluid pressure is dischargedinto a fluid pressure line. The pressure acting on the right face of thevalve the line 41 through the line I22 again forces the pilot valve tothe left, which action again reverses the master valve and the pistonascends. in its pumping stroke. Thus the same pumping action is obtainedthrough the pilot control valve by the use of the di'iferential pistonI2I in'place of the spring 32.

Referring to Figs. 10 and 11, the'piston provided with a hollow tubularextension I23 arranged to pass up through thepacking I24 in the headI25. The packing may be compressed by the gland member I26. The pistonextension I23 is longer than the cylinder I5 and protrudes above thehead I25 when the piston is in its lowermost position. Theupper end ofthe extension is provided with a small bore for receiving the polish rod25. A packing I21 and a gland member I28 are provided for sealing thepolish rod as it passes through the piston extension; A polish rod clampI29 is secured to the rod above the piston for locking it thereto. Acasing, not shown, may be slid over the piston extension and is alsoeffective on the left face of-the valve. The

communicating passageway H9 thus .nullifles the effectiveness of thepressure in the fluid discharge line 50 and the valve is actuated by thesmall differential piston 55 in the same manner described above.

In pneumatically operated pumping mechanism I a pop valve I20 may beprovided in the upper endof thecylinder l5 in the'sameposition as thegauge I0l described above. This valve is purely fastened to the head I25to keep the dirt and weather of! the piston surface.

; The p rposeof this piston extension is to permit the operator to raise,or lower the pump plunger in the well and thus properly space it fromthe bottom thereof to obtain the most effective operationof the wellpump. Again the well pump is made more readily accessible with thepolish rod extending above the apparatus.

In Fig. 12 a battery of fluid operated pumping ,mechanisms are shownconnected to a common source of fluid pressure supply as indicated bythe line no and the return or exhaust line m. 'f

These pumping units may be operated pneumatically or hydraulically froma common source of supply. The valves Ill and H8 together with theunions permit the removal of any one unit from the system withoutdisturbing the operation of the other units.

In'Flg. 13 the fluid pumping mechanism a supported in the horizontalposition by the base casting I32. A similar casting may beused forsupporting the other end of" the cylinder 15. In

this instance the polish rod 25- is replaced by a pull rod I22 whichextends to the depending arms of the pump Jacks I34. Theloadon thepolish has been converted from a hydraulically operrods wh ch a e sup od m th ute n r t y lkiee b ms he um e k is balanced to provide thepropergravity, return Iorce for movingp tlie piston}! or the'punipin'gmechanism to theleft, ,Whichis the samefas returning. it to the bottomor the cylinder in the, other -views. The, pistonin each instance isthus biased by the gravitational forces'oi the pumping mechanism andload Thusit is obvious that this fluid motor may be employed in cottontampers, baling'presses, stoker rams,

or any other type of mechanism requiring a continuous reciprocatingcycle of operation as long as some means is provided to bias or reversethe movementof the .pistonon the non-load stroke. 7 v

Iclaim: 1. In a fluid operated pumping'mechanism, the

combination of a cylinder, a piston working in the cylinder and biasedto move toward one end of the latter, a master valve arranged when inone position to admit-fluid under pressureto one end of the cylinder tomove the piston toward the other end and when in another position torelieve the iiuid pressure from the cylinder to permit the piston tojreturn,a pilot valve arranged to control the,operation of the mastervalve, two sets of control lines, one set entering the cylinder adjacentone end and the other adjacent the other end for regulating the strokeingline connecting the master valve to the first mentioned end of thecylinder, a fluid pressureactuated pilot valve arranged to control theoper'ationoi the master valve, a manually operated, ',valve forselecting the limit of the stroke of the piston at the second mentionedend of the cylinder, an idling control line connecting the operating,line with said selector valve, two control lines forming independentconnections between said selector valve and longitudinally spaced portsadjacent the second mentioned end of the cylinder, a second manuallyoperated valve for selectingv the limit of the stroke of the piston'at'the first mentioned end of the cylinder, two

control lines forming independent connections v between said secondselector valve and longitudinally spaced ports adjacent the firstmentioned end i of the cylinder, a passageway connecting each of saidselector valves with a common connection to the pilot valve, a checkvalve admitting flowirom the first selector valve to the pilot'ond'selector valve to actuate the pilot valve in the of thepiston,check valve mechanism, and unitary means for selectively connecting onecontrol line through said check valve mechanism from each set with thepilot valve for operating the same, the pressure of the ,fluid beingefiective through a selected control line at one end to ac- K pistontoward the other end of the cylinder and when in another position torelieve the fluid pressure and permit thepiston to return, an operatandthe position of either end other direction.

3.In a hydraulic pumping mechanism the combination of a cylinder, apiston working in 1 said cylinder and biased to move toward one end ofthe latter, fluid pressure-operated valvular means for admitting fluidunder pressure to and discharging it from the said end, of the cylinderto be eii'ective on one side of the piston,'two sets of control linesconnected with said cylinder, the connections of the individual lines ofeach set being in spaced relation, two passages connected to saidvalvular means and having oppositely working check valves therein, eachset of control lines having one of said passages operatively associatedtherewith, and means for selectively connecting one of the control linesof a set with the corresponding passage for varying the length of thepiston stroke in the cylinder.

' LOUIS A. RINGMAN.

